Fuel supply system for internal-combustion engines



M. c. WlLKS 2,619,947

COMBUSTION ENGINES FUEL SUPPLY SYSTEM FOR INTERNAL- Filed Ma y 9, 194';

2 SHEETS-SHEET l Dec. 2, 1952 M. c. WILKS 2,619,947

FUEL SUPPLY SYSTEM FOR INTERNAL-COMBUSTION ENGINES Filed May 9, 194 7" 2 SHEET --SHEET 2 'IIIIIIIII/ Fig.2

Patented Dec. 2, 1952 FUEL SUPPLY SYSTEM FOR INTERNAL- COMBUSTION ENGINES Maurice Carey Wilks, Solihull, England, assignor to The Rover Company Limited, Solihull, England Application May 9, 1947, Serial No. 747,068 In Great Britain May 24, 1944 Section 1, Public Law 690, August 8, 1946 Patent expires May 24, 1964 Claims.

This invention relates to liquid fuel supply systems for internal combustion engines, and particularly for road vehicle engines, of the type in which liquid fuel is injected by a variable delivery pump whose output is under the control of the driver, and in which the amount of air admitted to the air-inflow passage is automatically controlled by a spring-loaded valve. The object of the present invention is to provide improved means for efiecting the necessary variations in the correlation of the air inflow and the liquid fuel supply to suit diiierent power demands on the engine or other requirements.

In the accompanying sheets of explanatory drawings:

Figure 1 is a part sectional side View of a liquid fuel supply system embodying the invention.

Figure 2 is a similar view to Figure 1 illustrating a modification.

Figure 3 is a fragmentary view illustrating an additional feature of the invention.

In carrying the invention into eiiect as shown in Figure l, I employ a valve a of the poppet type for controlling the inflow of air to the air passage 12 of the engine. The stem 0 of the valve 0. has a pivoted and slidable connection with one end of a lever d which at its other end is pivoted to a fixed support e on one side of the air passage 2). In contact with one side of the lever d is arranged a slidable abutment which may be in the form of a roller or a plurality of coaxial rollers. The abutment also bears on a link g arranged parallel with the lever d, the ends of this link being pivotally supported by the adjacent ends of a pair of short inclined parallel-motion links it which at their other ends are pivoted to the support e, and which are loaded by a helical spring 2 of appropriate strength. The abutment f is connected by a link 7' to the regulator is of the variable delivery pump m by which liquid fuel is injected into the engine cylinder or cylinders, the regulator being operable under the action of the driver by, for example, a pedal (not shown) connected to the regulator through a link n. The arrangement is such that opening of the valve it depends on the suction in the air-inflow passage 2). The spring z tends to move the valve a to its closed position, and the pressure which it exerts on the valve depends on the position of the abutment f. Further the arrangement is such that the pressure exerted by the spring 1' is at its maximum when the pump regulator k is in the position of minimum delivery as shown, the spring loading being progressively diminished as the regulator is moved in the direction of the arrow towards the position of maximum delivery. The valve (1 is opened against the action of the spring 2' by the suction in the air-inflow passage 1).

By appropriate design the spring loading can be varied with movements of the pump regulator in a manner which ensures automatically the proper correlation of air inflow and fuel supply to suit the varying requirements of the engine.

In the example shown in Figure 2 the spring loaded linkage above described is dispensed with, and the abutment f is connected to one end of a tension spring i which at its other end is connected to a fixed anchorage, so that the abutment is held by the spring in contact with one side of the lever d, the pressure exerted by the spring on the valve a depending (as in the previous example) on the position of the abutment. Moreover, the said side of the lever d is curved slightly in the direction of its length.

As an alternative to the poppet type valve above described, I may employ an air valve of the butterfly type. In this case the opening movement of the valve is eifected through a lever by a piston slidable in a cylinder which is connected to the air inflow passage at the engine side of the valve, the latter being loaded by a spring mechanism substantially the same as that employed in either of the previously described examples.

With either of the valves above mentioned, I may provide a small lost motion connection between the slidable abutment and the pump regulator so that the quantity of fuel supplied in relation to air is slightly higher when the regulator is being moved towards the position of maximum fuel supply than when it is being moved in the opposite direction.

As exemplified in Figure 3, I may arrange in combination with the pump regulator lc an adjustable stop 0 for determining the position of maximum delivery, this stop being responsive to variations of ambient atmospheric pressure. The stop 0 may have the form of a rotary cam, or a slidable wedge, and may be operable through a rack p and pinion q or any other convenient mechanism by a deformable capsule 2" subject to atmospheric pressure.

The invention is not, however, restricted to the examples above described, as subordinate details may be modified to suit different requirements.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a liquid fuel supply system for internal combustion engines in which liquid fuel is injectecl by a variable delivery pump having a regulator and including a spring loaded suction operated air valve controlling the amount of air admitted to the air inlet duct of the engine, a control mechanism for the air inlet valve comprising, in combination, a pivoted lever connected to the valve for imparting closing movement thereto, a movable abutment engageable with an intermediate part of one side of the said lever, said abutment being adapted to be connected to the pump regulator, and spring loaded means engaged with said movable abutment to hold the latter in engagement with the said lever, the spring being arranged so that its force opposes opening movement of the valve by the suction in the duct, whereby the operation of the pump regulator causes displacement of the abutment along the valve operating lever and thereby varies the effect of the spring loading on the valve so that the air inflow and fuel supply are appropriately correlated to suit the requirements of the engine.

2. In a fuel supply system according to claim 1, an air inlet valve control mechanism comprising a stop for co-operating with the pump regulator for determining the position of the movable abutment at which the spring has its minimum efiect on the air valve, and means responsive to ambient atmospheric pressure for varying the position of the stop.

3. In a fuel supply system having an air inlet valve control mechanism according to claim 1, the combination including a linkage through which the spring acts on the movable abutment, the said linkage comprising a pair of parallelmotion links interconnected by a third link, the latter being engaged with the movable abutment.

4. In a fuel supply system having an air inlet valve control mechanism according to claim 1, the combination in which the spring is con- 4 nected at one endto the movable abutment and at the other end to a fixed anchorage.

5. In an air flow controlling mechanism for an internal combustion engine, the combination comprising a suction duct, a valve movable by suction in the duct to admit air thereto, a pivoted lever connected to the valve for imparting closing movement thereto, a movable abutment arranged in contact with an intermediate part of one side of the lever, a spring arranged to hold the movable abutment in contact with the lever and acting on the valve through the medium of the abutment and lever in the direction for opposing movement of the Valve by the suction in the duct, a manually movable member which is connected to the abutment and by which the abutment is movable along the adjacent side of the lever for varying the effect of the spring on the valve, and a linkage through which the spring acts on the movable abutment, said linkage comprising a pair of parallel-motion links interconnected by a third link, the latter being engaged with the movable abutment.

MAURICE CAREY VIILKS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,927,153 Conrader Sept. 19, 1933 1,931,541 Hesselman Oct. 24, 1933 1,931,557 Ringi Oct. 24, 1933 2,190,505 Wurr 1. Feb. 13, 1940 FOREIGN PATENTS Number Country Date 148,895 Great Britain Jan. 10, 1922 

